Surfaces often come into contact with, provide an environment for and provide a breeding ground for, potentially harmful pathogens. Non-limiting examples of surfaces include floors, table tops, and kitchen side boards, having any angle relative to ground level and of any shape, i.e. reference to surfaces is not limited to flat surfaces. A potentially harmful pathogen is any organism which can cause disease. Non-limiting examples of potentially harmful pathogens include bacteria, fungi, viruses, allergens, moulds and yeasts.
It is common to clean surfaces with agents which act to mitigate and/or destroy potentially harmful pathogens. The cleaning of surfaces in this way is beneficial to human and animal health, so as to prevent the spread of disease and mitigate the chances of a subject or subjects contracting a disease by coming into contact with potentially harmful pathogens.
One environment where it is particularly beneficial to clean surfaces with agents which act to mitigate and/or destroy potentially harmful pathogens is a veterinary environment, e.g. in a veterinary operating theatre.
Another environment where it is particularly beneficial to clean surfaces with agents which act to mitigate and/or destroy potentially harmful pathogens is a hospital environment, e.g. in a hospital operating theatre.
Another environment where it is particularly beneficial to clean surfaces with agents which act to mitigate and/or destroy potentially harmful pathogens is in a public amenity, e.g. the floor around a swimming pool.
There are many other environments where it is particularly beneficial to clean surfaces with agents which act to mitigate and/or destroy potentially harmful pathogens including, but not limited to, general household cleaning, hospitality venues, hotels, nursing homes, cruise ships and industrial food processing equipment.
Surfaces in veterinary operating theatres, hospitals, public amenities and other areas where people or animals could come into contact with harmful pathogens, should be cleaned regularly to prevent the build up of potentially harmful pathogens. Cleaning liquids used to clean surfaces include bleach solutions, solutions of washing up liquid, alcohol based disinfectants and general disinfectant liquid. One non-limiting example of a disinfectant liquid is Dettol™, as currently sold in the UK by Reckitt Benckiser™.
In using cleaning liquids, cleaning liquid is often transferred from storage, e.g. a bucket or a bowl, or other container, to a surface potentially contaminated with one or more pathogens.
In cleaning surfaces and/or water supplies, in particular in cleaning surfaces in hospitals, it is preferable for the anti-pathogen agent to be active in the presence of organic matter for a number of minutes, for example, up to 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80 and 90 minutes, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24 hours, and all other times in between. It is particularly preferable for the anti-pathogen agent to be active for at least 60 minutes up to 24 hours in a hospital environment so that a cleaner may continue to use a cleaning solution containing a cleaning liquid for a suitable amount of time, without having to repeatedly replenish the cleaning solution, for example because the activity of the anti-pathogen agent has decreased.
Known floor cleaning formulations include bleach solutions, these are effective at destroying pathogens on surfaces. However, bleach can be harmful to humans and animals in its own right. Solutions of washing up liquid have relatively weak anti-pathogen activity. Alcohol based disinfectants are used, but the alcohol, which has anti-pathogen activity, is relatively volatile so it evaporates off and has a relatively short anti-pathogen activity time.
It is preferable for cleaning liquids, specifically those used in a hospital environment, to have a relatively long (around 1 hour) anti-pathogen activity time so that after, for example, a floor has been mopped the anti-pathogen activity continues for long enough that pathogens do not have a chance to settle and/or grow in between cleaning cycles. Disinfectant liquid, e.g. Dettol™, is effective in its anti-pathogen activity, but many pathogens build up resistance to long-used disinfectants.
Cleaning liquids are also used in water supplies, e.g. in swimming pools, hot tubs (for example Jaccuzzis™) and spas where persons come into contact with communal water. Water supplies in swimming pools are often treated by chlorination. Water supplies in hot tubs are often treated by ozonation and/or by the introduction of halogens, e.g. bromine, into the water supply.
In the case of a particular pathogen, namely, Cryptosporidium parvum, contamination of swimming pool and recreational waters is a serious problem. Once the waters become contaminated, it is easy for the organism to be transmitted into humans and infection can occur from as little as 132 oocysts (DuPont et al., (1995), The Infectivity of Cryptosporidium parvum in Healthy Volunteers, 332(13): 855-859). The current treatment of these waters with chlorine is ineffective to eliminate this organism, as previous studies have shown that treatment with 4 ppm chlorine at pH 7 for 25 hours resulted in no decrease in cell viability as seen by the DAPI/PI assay, and only a 40% reduction in cell viability when using the excystation assay (Widmer, (2002), Molecular mechanisms of chemical inactivation of Cryptosporidium oocysts and Giardia cysts, AWWA Research Foundation).
There is a need for a new cleaning liquid which can be applied to surfaces, and used in water treatment, which is effective in mitigating pathogen counts and has limited, or no, harmful side effects on humans and animals.